The relationship between the index layer and the representation layer reminds one of the
hub-and-spoke model [1]}.
The hub is supposed to be located in the anterior temporal lobes (ATLs), which might be where concept indices
are consolidated. The hub is connected to several different areas (e.g., visual cortex, auditory cortex, orbitofrontal cortex), which might be part of the biological realization of the representation layer. Other hubs might be located in the
parietal and the temporal lobe [2]}
and maybe in the
frontal lobe [3]}.
